Mechanical combination locks are common on inexpensive padlocks, safe locks, and to control access to high security vaults. Combination locks require the user to "dial in" a secret combination, analogous to a password. The typical combination lock design involves a set of (usually three or four) disk tumblers around a spindle connected to the external dial. The disks are connected in sequence via interlocking cams such that one rotation of the dial engages the first disk, two rotations engage the second, and so on. The key idea that Tokarsky used when building his special table was that if a laser beam starts at one of the acute angles in a 45°-45°-90° triangle, it can never return to that corner. Any ball on the table can be pocketed, and each ball pocketed successfully earns the player one point. The map, as Alfred Korzybski used to point out, represents a territory, but the map what is billiards - click through the next site, not the territory.